Table 2.

Gut microbiota composition changes after microplastic exposure.

Species	Properties of Microplastics Used	Changes in Intestinal Microbiota	Reference
Chinese mitten crab (Eriocheir sinesis)	Polystyrene microplastics (5 μm)	Reduced diversity of gut microbiota The relative abundance of Firmicutes and Bacteroidetes decreased, and the relative abundance of Fusobacteria and Proteobacteria increased	[93]
Marine medaka (Oryzias melastigma)	Polystyrene micro- and nanoplastics (45 μm and 50 nm)	Increased α-diversity of gut microbiota in the exposed group The relative abundance of Bacteroidetes and Vicingus decreased The relative abundance of Lewinella, Pseudomonas, Thalassospira, and Parahaliea increased	[94]
Larval zebrafish	Polystyrene microplastics (1–4 μm)	Firmicutes, Bacteroidetes, Proteobacteria, and Verrucomicrobia changed significantly at the gate level At the genus level, the relative abundance of Aeromonas, Shewanella, Microbacterium, Nevskia, and Methyloversatilis increased significantly, while the relative abundance of Pseudomonas, Ralstonia, and Stenotrophomonas decreased significantly	[95]
Collembolans	Polyvinyl chloride microplastics	Increased gut microbiota diversity The relative abundance of Bacteroidetes decreased, and the relative abundance of Firmicutes increased	[96]
Mouse	Polyethylene microplastics (10–150 μm)	Increased diversity of gut microbiota The relative abundance of Staphylococcus increased, and the relative abundance of Parabacteroides decreased	[78]
Mouse	Polystyrene micro- and nanoplastics (50 μm and 0.5 μm)	At the gate level, the relative abundance of Firmicutes and α-Protebacteri was reduced A total of 6 and 8 bacterial species were altered by exposure to 0.5 and 50 μm micro- and nanoplastics, respectively, at the genus level	[77]
Mouse	Polystyrene microplastics (5 μm)	Changes in α-diversity and β-diversity occurred A total of 15 species were significantly altered at the genus level	[26]